Dr Joby Razzelliot
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jobium.bsky.social
Dr Joby Razzelliot
@jobium.bsky.social
5.3K followers 310 following 810 posts
Postdoc at the Natural History Museum studying microplastic pollution on Earth and looking for life on Mars. opinions are my own. he/him 🏳️‍🌈
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jobium.bsky.social
Did a wedding, got a husband, best day of my life!
Photo of two men wearing suits and crowns and walking through a cloud of confetti while grinning. The left man is wearing a green suit and a wreath of bay leaves on his head, the right man is wearing a pink suit with a flower crown on his head.
October 12, 2025 at 10:11 AM
jobium.bsky.social
I’m staring at the weather forecast for the weekend and regretting my decision to have an outdoor wedding.
Screenshot of a BBC Weather article showing a synoptic map of the United Kingdom, overlaid with barometric lines, large clouds of rain and the label “Storm Amy”. The rain clouds and storm fronts cover most of the UK and Ireland and reach as far south as Paris. A caption beneath the map says “Storm Amy moves in to the UK on Friday”
October 2, 2025 at 7:22 AM
jobium.bsky.social
I cannot look at my clematis without thinking of Mrs Malaprop
Photo of a clematis flower, consisting of six large purple petals surrounded a dense centre of yellow anthers
August 28, 2025 at 12:29 PM
jobium.bsky.social
I have redeemed myself with some focaccia
Photo of a square loaf of focaccia bread. It is studded with halved cherry tomatoes, rosemary sprigs, and some sliced tomatoes that have been shaped into a lobster of sorts. The bread itself is shiny with olive oil and it’s sitting on a red cutting board.
August 25, 2025 at 2:51 PM
jobium.bsky.social
When making tea loaves, it turns out plain flour plus baking powder (1st pic) is not exactly the same as self-raising (2nd pic). Not my best work in the kitchen, I must say.
Photo of a poorly made tea loaf cut in half. The loaf is brown, rectangular with a pale interior filled with raisins. The raisins are mostly at the bottom and there’s no peak to the loaf at all Photo of a well made tea loaf cut in half. The loaf is brown, rectangular with a pale interior filled with raisins. The raisins are evenly distributed and there’s a nicely rounded peak to the loaf
August 25, 2025 at 9:18 AM
jobium.bsky.social
Grant writing is significantly improved by cats, just FYI.
Photo of a silky black cat sitting on a blue and white cushion, looking to one side. She has white whiskers and a small patch of white hairs on her chest, but her otherwise completely black fur catches the light beautifully.
August 20, 2025 at 10:57 AM
jobium.bsky.social
But what do we see on Mars? We scanned the meteorite with SHERLOC and we see the same features, including a calcite blob full of terrestrial organics, igneous regions full of original martian organics, and bright Ce-bearing phosphates with that 340 nm fluorescence. A nice bit of ground truth!
Scientific figure in two parts. On the left, a close up image of the meteorite surface, taken on Mars, beneath that are 3 false-colour fluorescence maps of the same region taken at different points in the mission, showing a bright blue feature and several small yellow specks. On the right, multiple Raman and fluorescence spectra, showing peaks assigned to silicates, carbonate, and organic material. The figure compares spectra taken on Earth before launch to spectra taken on Mars, showing the same features, including a 340 nm fluorescence band associated with Cerium that is strongest in the area where the small flecks are.
August 15, 2025 at 10:35 AM
jobium.bsky.social
One of the risks with using UV fluorescence to look for organics is that it's also really good at detecting rare earth elements, like cerium. Turns out Ce3+ fluorescence is at 340 nm, and these bright specks are actually calcium phosphate grains that contain just 48 parts per million Ce.
Scientific figure in two parts. On the left, a close up fluorescence map with distinct specks of bright fluorescence at 340 nm, which coincide with phosphate-rich grains less than 100 micrometers wide. On the right, a high resolution SEM image (in black and white) with phosphate grains highlighted in purple, a corresponding LA-ICP-MS map shows that these grains are rich in cerium.
August 15, 2025 at 10:35 AM
jobium.bsky.social
So what else can we see? We have some lovely calcite features rich in terrestrial organic material, surrounded by an igneous matrix containing original martian organics. But what about those tiny blue spots? They are less than 100 micrometers wide and have a strong 340 nm fluorescence signature.
Scientific figure consisting of 8 images of the same 5x2.5 millimetre area of the meteorite surface. At the top is a photo of the area, showing a small white blob in the middle of a dark material. A fluorescence map shows the blob glowing brightly, surrounded by tiny blue specks. The other images are element maps and Raman intensity maps, showing the blob is rich in calcium, carbonate, and organic material, but the blue specks are not.
August 15, 2025 at 10:35 AM
jobium.bsky.social
The presence of organics (compounds made from carbon) in martian meteorites isn't news, they can form through normal geochemical processes. But Raman tells us that organics in those fluorescent cracks are too fresh to be from Mars, they must have entered the meteorite after it crashed on Earth.
Scientific figure plotting the Raman spectrum of two regions of the meteorite, the igneous maskelynite and the weathered calcite. The Raman peaks tell us what minerals are present, namely silicate and carbonate, but also tell us about organic composition. The weathered material has a broader G band and a stronger D band, consistent with less mature organic material, most likely terrestrial continuation rather than original material from Mars.
August 15, 2025 at 10:35 AM
jobium.bsky.social
The data from this meteorite is beautiful, UVF tells us that organics may be concentrated along cracks in the rock, while XRF tells us the meteorite itself is made of igneous minerals including iron-rich olivines, pigeonite, and shocked maskelynite.
A close up photo of the meteorite surface, showing distinct regions of different shades of brown, most less than a few millimetres in size. A very small bright white bit is noticeable in the bottom left corner A false-colour deep-ultraviolet fluorescence map of the same region of the meteorite. The surface is broken up by bright lines of fluorescence at 350-400 nanometres, appearing yellow-orange, while the rest of the surface is a green-blue from fluorescence at 300-340 nm A false-colour X-Ray fluorescence map of the same region of the meteorite. This map shows the presence of calcium (in red), iron (in green), and silicon (in blue), with distinct regions that are rich in each element. The calcium-rich regions follow thin lines across the surface, while the iron-rich regions are large blocks and the silicon-rich regions are small blobs that fill the remaining space
August 15, 2025 at 10:35 AM
jobium.bsky.social
Here's a picture of the meteorite on Mars, it's 1 of 10 calibration targets for the SHERLOC science instrument. It was included to provide a reality check: we know exactly what minerals and organics are in this rock, so if SHERLOC can see them it should be able to see them in other rocks too
Image of the SHERLOC calibration target pallet on the front of the Perseverance Mars rover, taken on sol 27 of the mission. The pallet is a long rectangle of brushed metal with 10 circular and rectangular holes, each containing a different material. The holes are 20 mm wide, and an arrow points to the upper middle material, showing a close up view of the meteorite target. The meteorite is circular, made up of a patchy texture of small grey-black and brown-beige regions
August 15, 2025 at 10:35 AM
jobium.bsky.social
Sayh al Uhaymir (SaU) 008 is a meteorite from Mars that landed in Oman and was found in 1999. The @nhm-london.bsky.social provided a piece of this meteorite to NASA to use on the Perseverance Mars rover mission, providing a reference for its scientific instruments.

Img credit: NASA/JPL-Caltech
Photograph of a hand wearing a purple nitrile glove and holding a small, flat piece of rock, about 5 centimetres long and 3 centimetres wide. Beneath the hand is an optical table, a shiny metal surface with regular holes that is reflecting a blue light from out of frame.
August 15, 2025 at 10:35 AM
jobium.bsky.social
Art wall update
Photo of a white wall behind a grey sofa, arrayed with framed art of various sizes
August 9, 2025 at 12:52 PM
jobium.bsky.social
It’s happening
Screenshot from the game Sid Meier’s Alpha Centauri, showing an isometric map of a green continent surrounded by blue water and populated by cities linked by roads
August 7, 2025 at 3:18 PM
jobium.bsky.social
Another custom spell deck I designed for a friend’s D&D character, a twilight cleric who is all about the balance between night and day. Perfect for a campaign about vampires!
Photo of four rectangular cards arranged in a fan on a grey background. The cards display the info for different D&D spells on their fronts, stylised to be either white text on black with a crescent moon symbol in the corner or as black text on white with a sun symbol. The backs of the cards shows the sun rising over a dark castle on a hilltop, and reflected beneath it is the same castle in darkness, with glowing windows lit up by a crescent moon.
July 31, 2025 at 8:32 AM
jobium.bsky.social
Spent my Friday evening talking to the public about how we’re exploring Mars at the Natural History Museum!
Photo of me, a white man with brown hair wearing a blue “Mars 2020” t-shirt and jeans, standing behind a trestle table covered in images, maps, and a Lego model of a Mars rover. Next to me is a large poster board showing a selfie taken by the Perseverance rover, and behind me is a wall covered in ichthyosaur fossils in glass cases.
July 26, 2025 at 8:46 AM
jobium.bsky.social
Went to the London Zoo Lates and saw lots of great animals. I think my favourite was the burrowing owl, but the derpy giant salamander is a close second
Photo of a Chinese giant salamander resting underwater. It has a long flat brown body with a wide derpy face and stubby fingers Long distance photo of a Pygmy hippo chowing down on some grass. The hippo is extraordinarily round and moist. Close up photo of a large butterfly resting on a leaf with its wings closed. The wings are brown and have striking circular markings that look like eyes Photo of a small burrowing owl perched on a branch, looking curiously at something with its bright yellow eyes
July 19, 2025 at 11:06 AM
jobium.bsky.social
My first 🍅 has appeared!
Close up photo of a small green tomato growing on a hairy stem. Two even smaller tomatoes can be seen further along the stem
July 12, 2025 at 12:45 PM
jobium.bsky.social
Big old buzzer
June 28, 2025 at 8:51 PM
jobium.bsky.social
My sweet peas are giving my garden a wonderful bi energy
Close up photo of a cluster of sweet pea flowers with delicate petals varying from pale blue to a warm purple
June 26, 2025 at 4:35 PM
jobium.bsky.social
I too have a black cat called Beetle, also utterly unblemished by thoughts.
Photo of a black cat standing imperiously on a table next to a pineapple plant.
June 24, 2025 at 12:37 PM
jobium.bsky.social
Attending my first AI conference to present this poster on how we can use spectroscopy and machine learning to improve how we identify plastic pollution eaten by wildlife
Image of an A0 academic poster entitled "Using FTIR and Raman Spectroscopy to Study Macro-Plastic Pollution Ingested By Seabirds". The poster has a black background and is broken into sections by angled grey-white boxes, each containing a scientific diagram and explanatory text. The blocks are entitled "FTIR vs Raman", "Materials Ingested by Shearwaters", "Biological Contamination", and "Classification by Machine Learning". The poster includes a large image in the top left hand corner of a thousand pieces of plastic pollution arranged into a spiral. Visit www.razzellhollis.com to learn more.
June 23, 2025 at 9:27 AM
jobium.bsky.social
Lurking in the herbs
Photo of a black cat lurking behind several potted herbs on a set of red shelves. The herbs are in full sunshine and their leaves are bright green. The cat’s black fire is catching the light as well, as are her eyes.
June 19, 2025 at 9:19 AM
jobium.bsky.social
Annual plug for my sticker shop! I design all sorts of queer stickers, space stickers, and queer space stickers. I do this mainly for fun but people buying them means I can afford to design more!

queerplanetdesigns.etsy.com
Photo collage of various stickers I’ve designed, including a ringed planet in the progress pride flag colours, a glittery crystal that says minerals rock, roundels that say “proud to be a scientist”, travel patches for places on Mars, and cats made of stars.
June 6, 2025 at 8:24 AM